[burger]

All models are wrong; some models are useful.  If your standard is that the model should predict the exact number of deaths on a given day, then I think you need to change your standards.

The death data is noisy.  For example, it was as low as 1156 deaths on April 26 before jumping up to 2470 on April 28.  That is why if you look at the shaded area, rather than the dotted line, you see that the model is predicting a range of deaths between about 400 and 4500.  Seeing a bit more than 2300 deaths is very much within the plausible range predicted by the model.

Broadly speaking, IHME is probably going to acquit itself pretty well.  It seems likely to me that we will be in the range of 100K - 240K deaths that it originally predicted, and while the first revised number of 60K deaths may have been too optimistic (and I'm still not sold on the most recently revised numbers saying that it will flatten out in the 75K range), this is about the precision one should expect for any sort of modeling exercise.

It certainly looks to be more accurate than the Imperial College model (predicting deaths in the millions) or a prominent economist who first predicted 500 deaths, then revised it to 5000 and then revised again to 50000 (while still falling short).

BC

There has been at least one actual study (a preprint--which I can't find now) looking at IHME and finding it quite inaccurate at the state level.  I've seen a lot of twitter posts comparing IHME a month ago with actual values and also finding major discrepancies in both the timing and the size of peaks in deaths.

I believe the Imperial College model was a counterfactual of sorts, showing what might happen with no containment methods.  So it wasn't wrong in any meaningful sense.

There are several other models out there--I haven't spent any time looking at them. I think we're actually at a point where we don't need model guidance anymore.  We know that social distancing reduces the spread of the virus.  I doubt that any model is precise enough to tell us how much infections will increase if you, say, open beaches vs. opening restaurants or other specific policy options.  These will all be experiments of sorts with a lot of unknowns.  Any model "guidance" at this point will just give us false confidence that we know what is going to happen.  We don't.

[burger]

All models are wrong; some models are useful.  If your standard is that the model should predict the exact number of deaths on a given day, then I think you need to change your standards.

The death data is noisy.  For example, it was as low as 1156 deaths on April 26 before jumping up to 2470 on April 28.  That is why if you look at the shaded area, rather than the dotted line, you see that the model is predicting a range of deaths between about 400 and 4500.  Seeing a bit more than 2300 deaths is very much within the plausible range predicted by the model.

Broadly speaking, IHME is probably going to acquit itself pretty well.  It seems likely to me that we will be in the range of 100K - 240K deaths that it originally predicted, and while the first revised number of 60K deaths may have been too optimistic (and I'm still not sold on the most recently revised numbers saying that it will flatten out in the 75K range), this is about the precision one should expect for any sort of modeling exercise.

It certainly looks to be more accurate than the Imperial College model (predicting deaths in the millions) or a prominent economist who first predicted 500 deaths, then revised it to 5000 and then revised again to 50000 (while still falling short).

BC

There has been at least one actual study (a preprint--which I can't find now) looking at IHME and finding it quite inaccurate at the state level.  I've seen a lot of twitter posts comparing IHME a month ago with actual values and also finding major discrepancies in both the timing and the size of peaks in deaths.

I believe the Imperial College model was a counterfactual of sorts, showing what might happen with no containment methods.  So it wasn't wrong in any meaningful sense.

There are several other models out there--I haven't spent any time looking at them. I think we're actually at a point where we don't need model guidance anymore.  We know that social distancing reduces the spread of the virus.  I doubt that any model is precise enough to tell us how much infections will increase if you, say, open beaches vs. opening restaurants or other specific policy options.  These will all be experiments of sorts with a lot of unknowns.  Any model "guidance" at this point will just give us false confidence that we know what is going to happen.  We don't.